Transportable bridge



June 6, 1967 VAUGOYEAU 3,323,157

TRANS PORTABLE BRIDGE Filed Jan. 22, 1965 5 Sheets-Sheet l IvmvToP:

* 22 HLEXHNDRE mum 7:56 (I A. VAUGOYEAU TRANSPORTABLE BRIDGE June 6, 1967 5 Sheets-Sheet 2 Filed Jan. 22, 1965 vi; C- L g g |K I, r \q 1 Tu [AWE/Wm? 9L EXHNDRE VnuwyMu gull a 7 June 6, 1967 A. VAUGOYEAU 3,323,157

TRANSPORTABLE BRIDGE Filed Jan. 22, 1965 5 Sheets-$heet 5 Fig.4.

I/WEA/TOA QLEXHNDRE Mar/goyzm/ United States Patent 3,323,157 TRANSPORTABLE BRIDGE Alexandre Vaugoyeau, Saint Marcel, Marseille, France Filed Jan. 22, 1965, Ser. No. 427,517 Claims priority, application France, Jan. 24, 1964, 20,438; Dec. 31, 1964, 20,835 1 Ciaim. (Cl. 14--1) The object of the invention is to provide improvements in an extensible bridge for military use in spanning wide gaps.

An embodiment of the bridge in accordance with the invention is shown in the accompanying drawings, in which:

FIG. 1 is a perspective view of the bridge;

FIG. 2a is a transverse section of the bridge, to a different scale;

FIG. 2b is a section of a detail;

FIG. 3 is a partial longitudinal section, to a larger scale, to show details of a latching device for extension members;

FIG. 4 is a transverse vertical elevation, to a larger scale, of an intermediate support device.

The bridge consists of two leaves interconnected by hinges 2 having a transverse hinge shaft 3.

Each leaf 1 has two external longitudinal frame members 4 and two internal longitudinal frame members 5, together providing a support frame, FIG. 2. These frame members each consist of a vertical web 8, of light alloy, having openings 9 to reduce its weight, and along the upper and lower edges of the web a pair of extruded light alloy girder sections 6 and 7. Since, owing to the span, the light alloy alone would not be sufficiently strong, the frame members 4 and are reinforced by sole plates 10, made of high tensile steel. The frame members 4 and 5 are interconnected by spaced transverse beams 11, of light alloy, consisting of panel elements 12, 13 and 14, connected to the webs 8 in such a manner that the external frame members 4 are positioned at the maximum permissible width of the bridge in unextended condition.

Along the central longitudinal axis of each leaf there is provided a channel 16 secured on the beams 11, and at each side of the channel 16 there are spaced longitudinal supports 17. Transversely across the top of the sole plates and supports 17 there are provided two lateral rows of fixed beam members 18 spaced longitudinally by gaps 19. The inner end of each beam member 18 rests on the channel 16.

In the gaps 19 are positioned a plurality of lateral extension members 20 pivoted on longitudinal pivot shafts 21 so as to be movable between an outer position, seen in the left hand side of FIG. 2a, and an inner position overlying the channel 16, seen in the right hand side of FIG. 2. The lateral extension members 20 which are coupled in groups of three by a wall 32 at their free end, can be latched in the selected position by a device shown in FIG. 3. The latch consists of a concave spherical dish 25, mounted by a rubber block 26 on a plate 24 carried on the beam members 18. A convex spherical cap 28 mounted by a rubber block 26 on a metal plate 27 secured on the outer wall of each outer member 20 can be snapped into engagement with said dishes 25.

The caps 28 are carried by the extension members 20 and dishes 25 are affixed to the beam members 18 at two points equidistant from the pivot shafts 21, so that when the extension members 20 are folded either towards channel 16 or towards the outside, the caps will engage in a dish in each extreme position and be firmly held therein.

When all the groups of extension members 20 are folded over towards the outside, the bridge then has its maximum width, and its track width is defined by the connecting walls 32, which are then aligned in a row. When the groups of extension members are folded over towards the channel 16, the width of the bridge is reduced to that defined by the external frame members 4. In this retracted transportation position, which is shown in the right hand half of FIG. 2a, the walls 32 are disposed in the channel 16, and the total depth of the bridge remains the same, because the extension members rest between the beams 18.

The beams 18, of inverted approximately T-section are relatively narrow, while the extension members 20, of approximately inverted U-section, are of considerably greater width. This feature provides, in the outwardly folded operating position, an exterior track surface which is gapped, the gaps being however narrow enough not to detract from the effectiveness of the track surface, but sufiiciently wide to give passage to the blast of explosions. Owing to the small width of the beams 18 the empty spaces left in the central part of the bridge are too large when the extension members 20 are folded over towards the outside. These spaces are accordingly covered by panels 34 of perforated sheet metal carried by a row of hinges of which the pivoting axis 37 is situated centrally above the channel 16. The panels 34, being pivoted on a longitudinal axis, can be raised to the vertical in order to enable the groups of extension members to be folded over, and can then be folded down again in order to fill the gaps left between the beams 18 when the bridge is in the widened position, or in order to cover over the extension members 20 when the latter are folded inwardly, thus forming a continuous track in both cases.

At the free extremity of each leaf 1 there is provided inclined access ramps 38. Under the frame members 4 and 5 and underneath the ramps 38 are corrugated metal sheets forming footings 39 for the bridge.

In the upper parts of the ramps 38 and between the internal frame members 5, there are provided two reinforced slots 40 to accommodate the hooks of a bridge-laying mechanism, not shown.

In order to increase the width of the ramps 38, when necessary, these latter are provided with sliding parts 381; which, in the retracted position of the bridge, rest on the extremities of the ramps 38.

In order to obtain a wider total track, it is possible to interconnect two identically similar bridges of the kind described. In this case, the groups of extension members are only folded over towards the exterior on the other side of each of the two bridges.

In order to increase the load-bearing capacity of the bridge, the invention provides double supports 45, FIG. 4 which can be moved into extended and stored positions, and which when extended can rest on the ground in the gap over which the bridge lies. These supports are mounted on short transverse shafts 3.

The supports consist of a tube 46 capable of pivoting about the shaft 3 with high friction provided by a bearing 46b of which the outer element can be secured more or less tightly on the shaft 3 by means of adjustable bolts. The tube 46 is affixed to the bearing 46b by an articulated cap 48. Another smaller tube 49 slides inside the tube 46, and its lower end rests on a base plate 50 to which is coupled by a ball and socket joint 51. The lower end of tube 46 has a reinforcement 52 of which the interior surface is frusto-conical. This reinforcement contains a socket subdivided into a number of chuck elements 53 of which the interior surface 54 is cylindrical and] corresponds in diameter to the external diameter of the tube 49, the exterior surface being of the same dimensions as the frustoconical portion of the reinforcement 52. A flange 54b acted on by springs 55, tends to thrust the socket 53 into reinforcement 52. When the tube 49 is drawn downwards the chuck elements 53 allow free passage, but when the tube 49 tends to move upwards, the chuck elements 53 acted on by springs 55 become jammed into the member 52 thereby gripping the tube 49 and holding it firmly against upward movement.

It is thus possible to adjust the length of the supports 45 in accordance with the depth of the gap to be spanned by the bridge. A series of tightening bolts 56 is provided to enable the chuck elements 53 and reinforcement 52 to be secured still more firmly, one inside the other, once the length of the supports 45 has been adjusted as required.

The springs 55 affixed to the flange 54 can be counteracted by a lever 57 which can be operated from the deck of the bridge by means of a handle. This handle enables the action of the springs to be counteracted while the bridge is being laid in position and to enable the supports 45 to be adjusted to the required length, even when the bottom of the gap to be spanned is inaccessible, utilizing the force of gravity on the tube 49.

During transportation the supports 45 are accommodated between the two leaves 1, but as and when the bridge is turned round and extended, in preparation for its laying, gravity acting on the supports 45 causes them to move into a vertical position. During this movement, chains 59, which are attached at one end to the lower part of the tube 46, and at the other end to the external frame members 4, are pulled taut until they are situated in the same plane. This tautening of the chains 59 causes the support 45 to incline towards the outside, because the pivot 48]) around which the support 45 rotates, is situated farther inside than the points at which the chains 59 are attached to the external frame members This inclination of the supports 45, however, is limited by a bracing chain 60. Owing to this inclination the gap between the base plates 50 becomes greater than the width of the bridge, and this gives it a considerable transverse stability which would not exist if, for example, the sup- L ports 45 were vertical and parallel, or were replaced with a single central support.

Strainer turnbuckles 61 make it possible, if necessary, to correct the length of the chains 59 and 6t) and to obtain an intermediate support of considerable rigidity. It should be noted that even when the supports 45 do not contact the bottom of the gap to be spanned, the entire system formed by the tubes 46 and the tautened chains 59 and 60 constitutes a considerable reinforcement of the bridge, by a form of king post effect.

I claim:

A bridge having: a support frame, a fioor comprising spaced transverse beam members on said support frame and being narrower than said frame, bridging panels over the beam members forming an upper surface, longitudinal pivot shafts extending through the ends of said beam members, a plurality of lateral extension members pivoted on said shafts intermediate said spaced beam members and adapted to be supported on the sides of said frame, longitudinal side strips connecting the ends of said lateral extension members and extending above the upper surfaces thereof, and aligned recesses in the upper central surfaces of said bridge beam members to receive said upstanding side strips when said lateral extension members are folded inwardly on their pivot shafts.

References Cited UNITED STATES PATENTS 2,556,175 6/1951 Frost 14--1 2,636,197 4/1953 Oclot 1427 3,010,128 11/1961 Gillois 14-1 FOREIGN PATENTS 859,277 3/1940 France. 1,339,046 8/1963 France.

844,916 8/1960 Great Britain.

JACOB L. NACKENOFF, Primary Examiner. 

